Grinding machines



Feb. 4, 1958 u w. ZALEWSKI 2,821,817

GRINDING MACHINES v Filed July 9, 1956 4 Sheets-Sheet- 1 Feb. 4, 1958 w. 'zALEWsKI GRINDING MACHINES 4 Sheets-Sheet 2 Filed July 9, 1956 Feb. 4, 1958 i y w. zALEwsKl y 2,821,817

GRIND'ING MACHINES Filed July 9, 1956. 4 Sheets-Sheet 3 Feb. 4, 1958 -w. zALEwsKl GRINDING MACHINES Filed July 9, 195e 4 Sheets-Sheet 4 NveN-roa WL A o yfLA W ZALEWJK/ United States Patent GRINDING MACHINES -Wladyslaw Zalewski, London, England Application July 9, 1956, Serial No. 596,660

Claims priority, application Great Britain July 22, 1956 Claims. (Cl. 51--123) This invention relates to tool and cutter grinding machines and has for its main object to provide such machines of relatively small size of simple and robust `construction which are readily portable and are suitable for bench and other mounting and for eld work, and which are adapted to operate upon tools, cutters and other parts of a great variety of types and-sizes in an expeditious and efficient manner.

In general, a grinding machine according to the invention comprises two main portions supported by a common base, namely the ldriving portion and the work-supporting portion, the driving portion including a vertically adjustable column carrying the base of an electric motor the horizontal shaft of which carries the grinding wheel, the position of the motor and grinding wheel being adjustable for cross movement in the direction of the horizontal axis of the motor shaft, whilst the work-supporting portion comprises a main table forming a main cross slide, which indirectly supports the work-piece and is constructed with guideways for limited cross movement parallel to the axis of the motor on either a fixed plain bar of circular or other section or, and preferably, two such bars arranged parallel, by adjustable spring means for the cutting movement and manually operable means for the return movement, the cutting movement being determined by an adjustable stop on the main table which abuts a fixed stop carried by the base, the main table carrying a superposed table angularly adjustable about a vertical axis coming in the vertical plane containing the axis of the motoryshaft, such superposed table having lixed parallel plain bars of circular or other section upon which a longitudinally movable slide, with suitable guideways, is mounted to run between adjustable stops, under the action of manually operable means. This longitudinally movable slide may have and preferably has an upper index table to turn on a vertical axis which coincides with that of the superposed table when the longitudinally movable slide is in the central position, which index table or the slide (when no index table is utilised) adjustably supports headstock-supporting means preferably comprising laterally extending parallel plain bars of circular or other section to which adjustable headstocks of various types for carrying the work-pieces are adjustably xed and according to the exact nature of the work-pieces and the operations to be performed.

In operation the work-piece is positioned between the headstock or equivalent means which may have angular or other indexing means to assist in the subsequent grinding; a hood or screen to the grinding wheel may also have indexing or similar means if required.

When the work-piece is set-up, the motor and grinding wheel, which are set to or can be set to the required height, have given thereto what may be termed the coarse cross movement to bring the grinding wheel into its starting position with respect to the work-piece.

During this action7 the main table `or main cross slide has been held in the fully retracted or out-of-action position, with the strength of the spring feeding means and the adjustable stop set to the particular operation to be carried out.

After starting the motor to run in one or the other direction, as required, the means holding the main table or main cross slide out of action are gradually released to allow the spring feed means to come into action. This, as will be realised, is suficient to move, in the feeding direction, the main table or cross slide and all the parts, including the work-piece, superposed upon and carried thereby. The work-piece is thus applied to the grinding wheel under what may be termed a gentle spring pressure, until the cross-cut operation is completed by the adjustable stop of the main table abutting the fixed stop associated with the base. The main table can now be retracted by its manually operable means and retained in the retracted position.

The work-piece can, if required, be moved longitudinally during the above-described cross-cutting, or subsequently, according to the nature of the operation. Similarly, the work-piece may be rotated continuously or otherwise, during or subsequent to the cross-cut and/ or longitudinal movements.

In order that the invention may be better understood, it will now be described with reference to the accompanying drawings which are given by way of example only and in which:

Fig. 1 is a front elevation with parts in section and parts broken away, of one form of machine constructed according to the invention.

Fig. 2 is a side elevationl of Fig. l in part axial section and with parts broken away.

Fig. 3 is a fragmentary sectional plan, to a larger scale, taken through the main table of the machine shown in Figs. l and 2.

Fig. 4 is a fragmentary sectional side elevation taken on the line IV--IV, Fig. 3.

Fig. 5 is a plan to the same scale as Fig. 4, of the supplementary table and certain associated parts of the machine shown in Figs. l and 2.

Fig. 6 is a plan of the longitudinally movable slide to the same scale as Figs. 3, 4 and 5, which is mounted upon the supplementary table.

Fig. 7 is a similar view of the upper index table and alssociated parts, carried by the longitudinally movable side.

Fig. 8 is a sectional side elevation on the line VIII-VIII, Fig. 6,

Figs. 9 and l0 are sectional views, to still larger scales, of constructional details,

Fig. l1 is a fragmentary sectional elevation of a modied construction of part of the machine shown in Figs. l and 2, also to a larger scale, and

Fig. 12 is a plan thereof.

In the drawings, 11 is a hollow base casting, preferably of an aluminium alloy, of general rectangular form with the narrow faces at the front and rear, open at the bottom and in the main closed at the top, which serves to house electrical components which may include a transformer 12 and a rectifier 13 to adapt the machine to the type of motor, voltage and current available. At the front it carries, as indicated in Fig. 2, a starting and stopping switch 14 for the motor and a supplementary switch 15 for determining the direction of rotation. At one side it is apertured towards the rear (not shown in the drawings) for the passage of a plug connected to the supply, and at the other side are located manual controls as and for the purposes hereafter described.

On the upper surface towards the rear the base 11 is apertured to take a anged vertical sleeve 16 of circular section open at the top and bottom, held in position by bolts passing through the flange, although it may be made integral with the base casting. In this sleeve is mounted a vertical hollow circular section column 17, so that it is an axially movable sliding fit therein, being held from rotation by a keyway 18 and key 19. At the rear the top of the sleeve 16 is vertically slotted at 2) and formed with lugs for cooperating with a lever-controlled clamping screw 21, for freeing the column 17 for vertical adjustment and for clamping it in any adjusted position.

The column 17 has an integral web 22 with a female threaded bore in its vertical axis, as shown, or parallel to this axis, which engages with an axially immovable vertical screw-threaded shaft 23. At the lower end this shaft has pinned thereto the boss of a bevel wheel 24, which boss is mounted in a bearing above which the screwed shaft has pinned thereto a bearing collar 26. 27 is a bevel wheel meshing with the wheel 24 and carried by a horizontal shaft 28 extending partly across the base and mounted in a bearing structure 29 to which the bearing 25 is connected. This structure (not further shown in the drawings) resembles an underslung framework having upwardly projecting end portions bolted to the underside of the top of the base. One end of the shaft 28 passes through a bearing in one side of the base and extends to the exterior where it has secured thereto a manipulating wheel 30 (Fig. l) for the raising and lowering ofthe vertical column 17.

At the upper end, this column 17 has a platform 31 with guideways 32 for a table 33 to which an electric motor 34 is secured so that the axis of its shaft 35 is horizontal and projects from the rear to the front. The motor is connected by a suitable flexible lead (not shown) to the appropriate parts in the base. the table 33 has secured thereto a toothed rack 36 with which meshes a toothed wheel 37 projecting through an opening in the platform 31 and mounted on a horizontal spindle 38 carried in bearings at the top of the column 17. One end of this spindle projects from the column and has secured thereto a manipulating wheel 39. By this means the motor 34 and the grinding wheel 40 carried by an extension of the shaft thereof, as hereafter explained, can be moved further towards or away from the front. At its front, the motor shaft 35 has coupled thereto an extension 41, shown to a larger scale in Fig. 9, supported by a ball bearing 42 carried by an additional framework 43 attached to the casing of the motor 34. This extension comprises a front solid shaft 99 to which the grinding wheel is clamped, and a split tubular shaft 44 which tits over the end of kthe motor shaft, and after this latter has been moved axially so that all its axial play is taken up, then the split tubular shaft 44 is clamped to the motor shaft by grub screws 45 turnable in the ange of a sleeve 46 mounted on the extension 41 and which holds it axially immovable in the bearing 42.

At the front, the upper part of the hollow base 11 is shaped to support the main table 47 which constitutes a main cross slide. For this purpose it includes supports for two fixed parallel plain steel bars of circular crosssection each coming parallel to a longer side of the rectangular base.

One of these circular section bars, 48, shown to the right of Figs. l and 4, is ixedly clamped .in bearings 49 integral with and fixed to the top of the base 11 so that its two ends project freely, one to the front and one to the rear, through the bearings a desired distance above the top of the base. The other circular section bar, 50, parallel to and at the same level as the bar l48, has lsimilarly shaped and disposed end portions. However, the intermediate portion is of square section and it is not clamped to bearings, but at its central position has a downwardly projecting foot terminating ina ball 51 sup ported in a footstep bearing 52 secured -to the underside of the topof -the base (Fig. l). `In placeof this arrange The underside of t 4 ment, however, the bar could be similar to the bar 48 and mounted on the base by clamping bearings such as 49.

The actual main table 47, which can be of aluminium or a light alloy, is of somewhat square shape in plan and resembles, as will be seen `from Figs. 1 to 4, an inverted shallow tray. What may be termed its front and rear downwardly extending flanges carry in clamped bearings, bearing sleeves 53 one of which is shown enlarged in Fig. l0. Each sleeve houses a double ball bearing 54 having balls in staggered relation at two levels which balls bear on the one hand on the exterior surfaces of the ends of the bars 48 or 50 and on the other hand on the interior surfaces of the sleeves 53. Each sleeve has a light compression spring 55 to keep the ball bearing 54 at all times on its associated bar, and a retaining washer 56 to prevent the said ball bearing from leaving the sleeve. The ball bearings may be omitted in some cases and the sleeves 53 slide directly on the bars.

From the above description and an inspection of the drawings, it will be appreciated that the maintable 47 has a limited front-to-back and back-to-'front movement (possibly about three-quarters of an inch) on the bars 48 and 50 and that the ends of these bars support the weight of the main table and the superstructure carried thereby.

The front flanged portion of the main table 47 carries bearings for two spindles 57 and 58, each projecting on the exterior for the fitting of a manipulating head. One of these, 57, on the interior varies the spring tension of a helical tension spring 59 connected on the one hand to a xed post 60 projecting from the base, and on the other hand to the main table 47. For this latter purpose the end of the spring 59 is connected to a sleeve 61 having a fine thread on its interior and keyed in a guide tube 62 integral with the spindle bearing, so that it can slide but not rotate in said tube. A screw 63 forming an extension of the spindle 57 and which is held from axial movement, screws into the sleeve 61 and the spindle 57 is capable of being turned to adjust the tension of the spring by a head or knob 64 shown dotted in Fig. 3. The constant tendency of the spring 59 is to pull said table 47 and the superstructure supported thereby towards the grinding wheel 40 carried by the motor shaft.

The other spindle 58 is similarly extended into a micrometer screw 65 screwing into a threaded sleeve 66 axially slidable` but held from rotation by being keyed in and to a guide tube 67 integral with the spindle bearing. The other end of the sleeve 66 carries a stop 68 which co-operates with a fixed stop 69 integral with and projecting upwardly from the top of the base 11. When the stop 68, termed the movable stop, cornes into contact with the fixed stop 69 (as shown in Figs. 3 and4) the movement to the rear of the main table ends.

The fixed stop 69 includes a sliding pin 70 so that when the movable stop 68 engages the fixed stop 69 at the completion of a cutting operation, a cam 71 (Fig. 4) controlled by a spindle 72 having a lever 73 on the exte rior and passing through the side of the base 11, can, by suitable manipulation of the said handle, effect the return of the main table and the parts held thereby and hold the table and the said parts in the retracted position until the handle 73 is released for a further feedingV operation. The mechanism includes, as shown in Fig. 4, a shaped two-armed lever 74 moved by the cam 71 and in turn imparting movement to the pin 70, movable stop andv rearwardly by the rearward movement of the main table until the position of Fig. 4 is re-attained. The position agsaigsrv of the movable stop 68 is adjusted by turning the spindle 58 by means of the indexing knob 100`(Fi'g.-`4).

The upper surface of the main table 47 is formed as a circular bed plate and this has mounted thereon to move around a vertical axis coming in the vertcal'plane containing the axis of the motor shaft, a superposed table 75 which can be of aluminium or a light alloy and which has a circular index by which it can be set into any required position. lt can be clamped and unclamped from the main table by clamping bolts 76 (only one of which is shown in Fig. l) by a cam spindle and lever means of known type indicated by the reference 77, Fig. 1.

This superposed table 75 is shown in plan view from above in Fig. 5 and the upper part thereof includes parallel plain steel bars 7 8 of circular section, arranged symmetrically in relation to the vertical axis of rotation, which in the zero position of the setting come parallel to the front and back of the machine and at rlghtangles to the axis of the motor shaft.

Manual operating means comprising an exterior handle S3 shown dotted in Fig. 2 and a cross shaft 79 with a toothed pinion 80 engaging a rack 81, permit a slide 82 carried by the superposed table 75, and which can be of aluminium or a light alloy, to be given longitudinal movement. The arrangement of the pinion and rack drive 80-81 preferably is of the known type in which the spindle can be pulled forwardly to disengage lthe, pinion from the rack (full-line position of Fig. `5) tov leave the slide free to be moved laterally by hand and pushed back (dotted line position, Fig. 5) to engage the pinion with the rack for movement of the slide from the handle 83.

The pinion and rack drive can be replaced by other mechanism, for example by a friction wheel drive, which may includeresilient means to increasev the grip between the wheel and the runner.

The slide 82 is shown in plan from above in Fig. 6 and in section in Fig. 8 and comprises four saddle-like members 84 each having bearing rollers 85 mounted in needle bearings, riding on the plain parallel bars 78 of the superposed table 75, togetherwith lower rollers 86 running on the underside of the said bars, carried by a common spindle 87 kept pulled upwardlyl by springpressed headed pins 88 working in bores in the slide 82.

The longitudinal movement of this slide 82 lcan be as desired between spaced stops one of which, 89, is shown in Fig. 1, which are adjustably carried by bars 90 at the front of the superposed table 75 and which co-operate with stops 91 beneath and integral with'the longitudinally moving slide. screening the open upper portions of the superposed table 75, the slide 82 working thereon may, as shown, have laterally projecting screening plates 92 with downturned flanges 93.

The longitudinally movable slide 82 also has a central bed plate upon which an upper index table 94, of aluminium or a light alloy, shown in plan in Fig. 7, is mounted to turn and to be held in any suitable position by clamping screws and nuts 98. This index table 94 turns on an axis which coincides with that of the superposed table 75 when the longitudinally movable slide 82 is in its central position,'and the said table 94 carries parallel longitudinally extending plain steel bars 95 of circular section, arranged symmetrically in relation to the vertical axis of rotation and the free laterally extendl ing portions of which have clamped thereto headstocks such as 96 and 97 of any suitable nature.

It will be obvious that the structural arrangement yof the headstocks can be varied within extremely wide limits as they must be in accordance with the tools, cutters, or other Workpieces being operated upon.

Although the axis of the motor shaft in its normal position of operation is at right angles to the `longitudinal bars carried by the superposed table, in some cases the motor` basemay have an additional adjustment whereby it can be turned about a vertical axis so that said'hori- For the purpose of 'guarding or '6 zontal axis can come at an angle other than a right angle to said bars. Such a construction is indicated in Figs. 11 and 12 which show details of a modification. In these figures, 33 is the table which comes at the top of the column 17. This has a circular recess 99 in its upper surface and concentric therewith a circumferential groove of dovetail section. The base plate 101 for the electric motor 30 is circular in plan and has a circular projection on its underside forming a short vertical stub axle 102 to it into and adapted to turn in the recess 99. This motor base 101 is adapted to be secured to the table 33 in various positions by bolts and nuts 103, the bolts having conical heads 104 which tit the bevelled sides of the dovetail groove 100.

By this construction the electric motor 34 can be set so that the axis of its shaft 35, represented by the dot and `dash lines in Fig. 12, can be set into the required angular positions in relation to the longitudinal bars carried bythe superposed table. The vertical axis about which the motor base 101 turns can be coincident with that of the-vertical column, but preferably is located nearer to the actual grinding wheel.

Throughout the specication the main table has been described as movable from front to back or vice versa in the sense that this movement on its supporting bar or bars is at right angles to the longitudinal bars carried by the superposed table. However, it should be understood that this angle can be a desired amount more or less than a right angle and still be regarded as movement from the front t0 back and back to front.

Although for convenience of description the spring means for effecting the cutting feed has been described as a helical tension spring, it is obvious that other spring means may be employed of a single or compound nature, provided the workpiece is fed to the cutter by the resilient pressure thereof which enables the work to give if necessary.

As will be appreciated, grinding machines in accordance with the invention are fabricated from mixed materials, in the main aluminium or other light alloys, iron and steel, and this is advantageous in that such combinations of materials have vibration-damping properties.

What I claim is:

l. A tool and cutter grinding machine comprising a base, a column adjustable along its vertical axis supported by and projecting upwardly from said base towards the rear thereof, an electric motor with a horizontal driving shaft the axis of which extends from the front to the rear of the machine and having a base adjustably sup-y tance from the front to the rear and from the rear to,

the front on the said table supporting plain bar, adjustable spring means connected on the one hand to the main table and on the other hand to the base for moving the main table from the front to the rear, manually operable means mounted on the base for moving the main table from the rear to the front, lixed stop means carried by the base to limit the rear movement of the main table, adjustable stop means carried by the main table and cooperating with the said fixed stop means for varying the' amount of the movement of the main table, a superposed table carried by and moving with the main table and mounted thereon so as to be angularly adjustable about a vertical axis which is located in the vertical plane con` taining the horizontal axis of the driving shaft, laterally extending spaced-apart and parallel slide-supporting plain bars arranged on horizontal axes at right angles to the axis of the driving shaft fixed to and carriedabove and by the superposed table, a longitudinally movable slide mounted to movey within limits on said ,slide-supporting:

plain bars, means carried by the superposed table and said slide for imparting movement to the slide, and means supported by the longitudinally movable slide for carrying headstocks and other work-supporting means, all for the purposes set forth.

2. A tool and cutter grinding machine comprising a base, a column adjustable along its vertical axis supported by and projecting upwardly from said base towards the rear thereof, an electric motor with a horizontal driving shaft the axis of which extends from the front to thc rear of the machine and having a base adjustably supported at the top of the column for horizontal movement, a grinding wheel mounted on and projecting from the front end of said driving shaft, spaced-apart and parallel table-supporting plain bars arranged on horizontal axes parallel to the axis of the driving shaft and mounted in fixed positions at they front portion of and above the base, a main table forming a main cross slide mounted to move a limited distance from the front to the rear and from they rear to the front on the said table-supporting plain bars, adjustable spring means connected on the one hand to the main table and on the other hand to the base for moving the main table from the front to the rear, manually operable means mounted on the base for moving thc main table from the rear to the front, fixed stop means carried by the base to limit the rear movement of the main table, adjustable stop means carried by the main table and co-operating with the fixed sto-p means for varying the amount of movement of the main table, a superposed table carried by and moving with the main table and mounted thereon so as to be angularly adjustable about a vertical axis which is located in the vertical plane containing the horizontal axis of the driving shaft, lateryally extending spaced-apart and parallel slide-supporting plain bars arranged on horizontal axes at right angles to the axis of the driving shaft fixed to and carried above and by the superposed table, a longitudinally movable slide mounted to move within limits o-n said slide-supporting plain bars, meansk carried by the superposed table and said slide for imparting movement to the slide, an upper index table carried by and moving with said slide and mounted thereon so as to be angularly adjustable about a vertical axis which coincides with that of the superposed table when the said longitudinally movable slide is in the mid position between its extremes of movement, and laterally extending horizontal plain bar means secured to the upper index table for carrying headstocks and other work-supporting means, all for the purposes set forth.

3. A tool and cutter grinding machine comprising a base, a column adjustable along its vertical axis supported by and projecting upwardly from said base towards the rear thereof, an electric motor with a horizontal driving shaft the axis of which extends from the front to the rear of the machine and having a base adjustably supported at the top of the column for horizontal movement, a grinding wheel mounted on and projecting from the front end of said driving shaft, spaced-apart and parallel table-supporting plain bars arranged on horizontal axes parallel to the axis of the driving shaft and mounted in xed positions at the front portion of and above the base, a main table forming a main cross `slide mounted to move a limited distance from the front to the rear and from the rear to the front on the said table-supporting plain bars, adjustable spring means connected on the one hand to the lmain table and on the other hand to the base for moving the main table from the front to the rear, manually operable means mounted on the base for moving the main table from the rear to the front, fixed stop meansy carried by the base to limit the rear movement of the main table, adjustable. stop means carried by the main table and co-operating with the fixed stop means for varying the amount of movement of the main table, a. superposed table carriedy by and. moving with the main table and mounted thereon sotassto'he vangularly, adjustable abouta vertical axis whichislocated in the vertical plane containing the horizontalaxis of the driving shaft,.laterally extending spaced-apart and parallel slide-supporting plain bars arranged on horizontal axes at right angles to the axis of the driving shaft fixed to and carried above and by the superposed table, a longitudinally movable slide mounted to move within limits on said slide-supporting plain bars, a toothed rack fixed beneath said slide, a manually operable spindle having. a horizontal axis parallel to that of the driving shaft and mounted in bearings integral with the superposed table, a gear-wheel mounted on said spindle and which meshes with said rack, an upper index table carried by and vmoving with said slide and mounted thereon so as to be angularly adjustable about a vertical axis which coincides with that of the superposed table when the said longitudinally movable slide is in the mid lposition between its extremes of movement, and laterally extending horizontal plain bar means secured to the upper index table for carryingheadstocks and other work-supporting means, all for the purposes set forth.

4. A tool and cutter grinding machine comprising a base, a vertically arranged sleeve in xed relation to the base, a hollow cylindrical column adapted to slide but not to rotate in said sleeve, a female threaded member on theI interior of and integral with sa-id column, a vertically mounted screw-threaded shaft in screwed relation with said threaded member, means for holding said screwthreaded shaft from axial movement, a horizontal shaft mounted in the base and having a manipulating handle on the exterior, gearing between the said two shafts and means for freeing the column from or for clamping said column in any adjustedv position in the said sleeve, an electric motor with a. horizontal driving shaft the axis of which extends from the front to the rear of the machine and having aV base adjustably supported at the top of the column for horizontal movement, a grinding wheel mounted on. and projecting from the front end of said driving shaft, spaced-apart and parallel table-supporting plain bars arranged on horizontal axes parallel to the axis of the driving shaft andV mounted in fixed positions at the front portion of and above the base, a main table forming a main cross slide mounted to move a limited distance from the front tothe rear and from the rear to the front on the said table-supporting plain bars, adjustable spring means connected on the one hand to the main table and on the other hand to the base for moving the main table from the front to the rear, manually operable means mounted on the base for moving the main table from the rear to the front, fixed stop means carriedv by the base to limit the rear movement of the main table, adjustable stop means carried by the main table and co-operating with the fixed stop means for varying the amount of movement of the main table, a superposed table carried by and moving with the main table and mounted thereon so as to be angularly adjustable about a vertical axis which is located inthe vertical plane containing the horizontal axis of the driving shaft, laterally extending spaced-apart and parallel slide-supporting plain bars arranged on horizontal axes aty right angles to the axis of the driving shaft fixed` to and carried above and by the superposed table, a longitudinally movable slide mounted to move within limits on said'slide-supporting plain bars, a toothed rack fixed beneath said slide, a manually operable spindle having a horizontalv axis parallel to thatv of the driving shaft and mounted in bearings integral with the superposed table, a gear-wheel mounted on said spindle and which meshes with said rack, an upper index table carried by and moving with said slide and mounted thereon so as to be angularly adjustable about a vertical axis which coincides with that of the superposed table when the said longitudinally movable slideis in the mid position between its extremes. ofV movement, and laterally extending `horizontal plain bar means secured to the upper index table for carrying headstocks and other work-supporting means, all for the purposes set forth.

5. A tool and cutter grinding machine comprising a base, a vertically arranged sleeve in fixed relation to the base, `a hollow cylindrical column adapted to slide but not to rotate in said sleeve, a female threaded member on the interior of and integral with said column, a vertically mounted screw-threaded shaft in screwed relation with said threaded member, means for holding said screw-threaded shaft from axial movement, a horizontal shaft mounted in the base and having a manipulating handle on the exterior,` gearing between the said two shafts and means for freeing the column from or for clamping said column in any adjusted position in the said sleeve, an electric motor with a horizontal driving shaft the axis of which extends from the front to the rear of the machine and having a base adjustably supported at the top of the column for horizontal movement, a horizontalguideway at the top of the column and in fixed relation thereto, a table mounted on said guideway to move from the rear to the front and vice versa, means for securing the base of the motor to said table, a toothed rack lixed beneath said table, a horizontal spindle carrying bearings at the top of the column projecting to the exterior, a hand-wheel mounted on such projecting portion and a toothed pinion turning with said spindle and meshing with said rack, a grinding wheel mounted on and projecting from the front end of said driving shaft, spaced-apart and parallel table-supporting plain bars arranged on horizontal axes parallel to the axis of the driving shaft and mounted in xed positions at the front portion lof and above the base, a mainl table forming a main cross slide mounted to move a limited distance from the front to the rear and from the rear to the front on the said table-supporting plain bars, adjustable spring means connected on the one hand to the main table and on the other hand to the base for moving the main table from the front to the rear, manually operable means mounted on the base for moving the main table from the rear to the front, xed stop means carried by the base to limit the rear movement of the main table, adjustable stop means carried by the main table and co-operating with the fixed stop means for varying the amount of movement of the main table, a superposed table carried by and moving with the main table and mounted thereon so as to be angularly adjustable about a vertical axis which is located in the vertical plane containing the horizontal axis of the driving shaft, laterally extending spaced-apart and parallel slidesupporting plain bars arranged on horizontal axes at right angles to the axis of the driving shaft fixed to and carried above and by the superposed table, a longitudinally movable slide mounted to move Within limits on said slide-supporting plain bars, a toothed rack fixed beneath said slide, a manually operable spindle having a f horizontal axis parallel t-o that of the driving shaft and mounted in bearings integral with the superposed table, a gear-wheel mounted on said spindle and which meshes with said rack, an upper index table carried by and moving with said slide and mounted thereon so as to be angularly adjustable about a vertical axis which coincides with that of the superposed table when the said longitudinally movable slide is in the mid position between its extremes of movement, and laterally extending horizontal plain bar means secured to the upper index table for carrying headstocks and other work-supporting means, all for the purposes set forth.

6. A tool and cutter grinding machine comprising a base, a vertically arranged sleeve in xed relation to the base, a hollow cylindrical column adapted to slide but not to rotate in said sleeve, a female threaded member on the interior of and integral with said column, a vertically mounted screw-threaded shaft in screwed relation with said threaded member, means for holding said screw-threaded shaft from axial movement, a horizontal shaft mounted in the base and having a manipulating handle on the exterior, gearing between the said two shafts and means for freeing the column from or for clamping said column in any adjusted position in the said sleeve, an electric motor with a horizontal driving shaft the axis of which extends from the front to the rear of the machine and having a base adjustably supported at the top of the column for horizontal movement, a horizontal guideway at the top of the column and in fixed relation thereto, a table mounted on said guideway to move from the rear to the front and vice versa, means for securing the base of the motor to said table, said means including further means to permit the motor base to be turned about a vertical axis, a toothed rack fixed beneath said table, a horizontal spindle carrying bearings at the top of the column projecting to the exterior, a hand-wheel mounted on such projecting portion and a toothed pinion turning with said spindle and meshing with said rack, a grinding wheel mounted on and projecting from the front end of said driving shaft, spacedapart and parallel table-supporting plain bars arranged on horizontal axes parallel to the axis of the driving shaft and mounted in fixed positions at the front portion of and above the base, a main table forming a main cross slide mounted to move a limited distance from the front to the rear and from the rear to the front on the said table-supporting plain bars, adjustable spring means connected on the one hand to the main table and on the other hand to the base for moving the main table from the front to the rear, manually operable means mounted on the base for moving the main table from the rear to the front, xed stop means carried by the base to limit the rear movement of the main table, adjustable stop means carried by the main table and co-operating with the fixed stop means for varying the amount of movement of the main table, a superposed table carried by and moving with the main table and mounted thereon so as to be angularly adjustable about a vertical axis which is located in the vertical plane containing the horizontal axis of the driving shaft, laterally extending spaced-apart and parallel slide-supporting plain bars arranged on horizontal axes at right angles to the axis of the driving shaft fixed to and carried above and by the superposed table, a longitudinally movable slide mounted to move within limits on said slide-supporting plain bars, a toothed rack fixed beneath said slide, a manually operable spindle having a horizontal axis parallel to that of the `driving shaft and mounted in bearings integral with the superposed table, a gear-wheel mounted on said spindle and which meshes with said rack, an upper index table carried lby and moving with said slide and mounted thereon so as to be angularly adjustable about a vertical axis which coincides with that of the superposed table when the said longitudinally movable slide is in the mid position between its extremes of movement, and laterally extending horizontal plain bar means secured to the upper index table for carrying headstocks and other work-supporting means, all for the purposes set forth.

7. A tool and cutter grinding machine as claimed in claim 2 in which one of the plain bars for supporting the main table is clamped in an intermediate portion of its length to the base to leave its ends free, and the other is provided with a downwardly projecting foot in an intermediate position which foot terminates in a bali, said ball being housed in a footstep bearing secured to the base to leave the ends of the bar free, the four ends of the bars serving slidingly to support the main table by means of four bearing sleeves carried by the main table and engaging over the ends of the bars.

8. A tool and cutter grinding machine as claimed in claim 2 in which the adjustable spring means is connected to the main table through a fine screwed member adapted to move axially but held from rotation, the screw-threaded portion of such member being engaged l by a co-operating screw held from axial movement and mounted on a spindle projecting from the main table and controlled by a manipulating 'head on said projecting portion.

9. A tool and cutter grinding machine as claimed in claim 2 in which the adjustable spring` means is connected to the main table through a ne screwed member adapted to move axially but held from rotation, the screw-threaded portion of such member being engaged by a co-operating screw held from axial movement and mounted on a spindle projecting from the main table and controlled by a manipulating head on said projecting portion, and further in which the adjustable stop of the main table is carried by and subject to the movements of a micrometer screwed member adapted to move axially but held from rotation, the screw-threaded portion of said member being engaged by a co-operating micrometer screw held from axial movement and mounted on. a spindle projecting from the main table and controlled by a manipulating head on said projecting portion.

10. A tool and cutter grinding machine as claimed in claim 2 in which the adjustable spring means is connected to the main table through a fine screwed member adapted to move axially but held from rotation, the screw-threaded portion of such member being engaged 12 by a cca-operating screw held from axial movementand mounted on a spindle projecting from the main.v table and controlled by a manipulating head on said projecting portion, in which the adjustable stop of the main table is carried by and subject to the movements' of a micrometer screwed member adapted to move axially but held from rotation, the screw-threaded portionv of such member being engaged by a co-operating micrometer screw held from axial movement and mounted on a.

spindle projecting from the main table and controlledl References Cited in the tile of `this patent UNITED STATES PATENTS Thompson July 3U, 1901 Walker Nov. 4, 1902' Wessman Jan. 14, 1947- 

